VANCOUVER, April 28, 2013 /PRNewswire/ – Capstone Mining Corp. (“Capstone”)
(TSX: CS) today announced that it has entered into a definitive
agreement with BHP Copper Inc., a subsidiary of BHP Billiton Ltd. (“BHP
Billiton”), to purchase BHP Billiton’s wholly-owned Pinto Valley copper
mining operation and the associated San Manuel Arizona Railroad Company
(“SMARRCO”) in Arizona, USA for US$650 million.

The Pinto Valley Mine is located in the Globe-Miami mining district in
Arizona, approximately 125 kilometres east of Phoenix. It is projected
to produce 130 – 150 million pounds of copper in concentrate and
approximately 10 million pounds of copper cathode annually, along with
by-product molybdenum and silver, at an estimated cash cost of
approximately $1.80 per pound, net of by-product credits, for the first
five years of production.

“Pinto Valley represents a unique opportunity to acquire a mid-sized
producing copper mine in a well-established and low-risk mining
jurisdiction with a significant mineral resource,” said Darren Pylot,
President and CEO of Capstone. “This acquisition gives Capstone our
third producing mine with a long mine life and is consistent with
Capstone’s strategy of building an intermediate copper producer focused
in the Americas.”

“The purchase price and financing structure allows us to maintain our
financial flexibility, retaining approximately $135 million in cash,”
continued Mr. Pylot. “The retained cash, combined with the immediate
cash flow and low on-going capital requirements expected from Pinto
Valley and our current operations, provides us with the necessary
financial resources to continue to fund our development projects.”

“During our extensive due diligence process we were very impressed with
the world-class operations and the solid workforce and management team
that are in place at Pinto Valley. We are looking forward to the Pinto
Valley employees joining Capstone as we jointly prepare to realize the
full value of the Pinto Valley asset well into the future,” concluded
Mr. Pylot.

Investment Highlights

• Immediately transforms Capstone into an intermediate copper producer.
• Annual production from Pinto Valley of 130 – 150 million pounds of
  copper provides immediate >160% increase in Capstone’s copper
  production.
• First five year estimated cash cost of $1.80 per pound (net of
  by-product credits).
• Further asset diversification into Arizona, USA, one of the world’s most
  favorable mining jurisdictions and aligned with Capstone’s existing
  assets.
• Work underway aimed at upgrading the 1 billion tonne Measured and
  Indicated (“M&I”) Mineral Resource to extend operations beyond the
  current reserve life reported by BHP Billiton.
• Maintained and managed to BHP Billiton’s world-class standards.
• All necessary established infrastructure, permits and skilled workforce
  in place.

Transaction Overview

The purchase price is being paid in cash and is subject to customary
adjustments. The purchase price will be satisfied from Capstone’s
existing $200 million Senior Secured Revolving Credit Facility ($176
million available) and from a new 2.5-year, $200 million Senior Secured
Reducing Revolving Credit Facility, that are respectively committed and
underwritten by The Bank of Nova Scotia, and cash on hand. The new
facility will include customary covenants and closing conditions,
including closing of the Pinto Valley acquisition, and will bear
interest at market rates. The acquisition agreement is not conditional
upon financing.

Under the terms of the agreement, Capstone is committed to maintaining
Pinto Valley’s existing environmental standards and will provide
financial assurances reasonably necessary to obtain regulatory
approvals for the transfer of the applicable permits. BHP Billiton
employees working at Pinto Valley and SMARRCO will become employees of
Capstone as part of the transaction.

The purchase agreement includes typical closing conditions, including
regulatory approvals. Closing of the transaction is expected to occur
in the third quarter of 2013. There can be no assurances the
acquisition or the financing will close.

Operational Highlights

The Pinto Valley Mine successfully restarted operations on schedule in
December 2012 at a capital cost of $194 million (including
approximately $60 million for a new mining fleet), which will be fully
funded by BHP Billiton. The restart is progressing well, and is on
schedule to achieve a run-rate of over 50,000 tonnes per day by the end
of 2013.

The mine is projected to employ approximately 650 employees and has all
necessary established infrastructure. Key contracts will be in place at
closing of the transaction for water, power and access to markets, and
a Transitional Services Agreement will be executed with BHP Billiton to
provide various administrative services through a defined transition
period.

Local regulatory and community support has been demonstrated for the
mine during both prior operations and the recent re-start. Arizona is
among the world’s most favorable mining jurisdictions with respect to
tax, regulation and labour.

Mineral Resources

The Pinto Valley property includes a significant amount of
mineralization not included in BHP Billiton’s publicly-reported Mineral
Reserve estimate. Capstone has completed the following NI 43-101
compliant Mineral Resource estimate for the global identified resource,
with a technical report to be filed within 45 days.

Mineral Resource Estimate, February 28, 2013, at a 0.25% COG*

	Metric Tonnes (M)	Copper (%)	Molybdenum (%)	Contained Copper (k tonnes)	Contained Molybdenum (M lbs)
Measured (M)	402	0.38	0.010	1,544	40
Indicated (I)	566	0.33	0.008	1,870	45
Total M&I	968	0.35	0.009	3,414	85
Inferred	45	0.33	0.009	146	4

* Totals may not sum exactly due to rounding. This estimate had not been
adjusted for the three months of mining from start up to February 28,
2013.

Mineral resources that are not mineral reserves do not have demonstrated
economic viability. Mineral resource estimates do not account for
mineability, selectivity, mining loss and dilution. These mineral
resource estimates include inferred mineral resources that are normally
considered too speculative geologically to have economic considerations
applied to them that would enable them to be categorized as mineral
reserves. There is also no certainty that these inferred mineral
resources will be converted to measured and indicated categories
through further drilling, or into mineral reserves, once economic
considerations are applied.

The current Pinto Valley plan of operation, based on BHP Billiton’s
publicly reported reserves, projects a 5-year operation, which is fully
permitted with mining presently underway. Capstone believes that
considerable potential exists to upgrade the M&I Mineral Resources into
reserves, potentially extending the operation meaningfully beyond the
current reserve life as reported by BHP Billiton. A Preliminary
Feasibility Study (“PFS”) is underway that will target the M&I Mineral
Resources for potential conversion to reserves, with expected
completion in 2013. The PFS will consider the potential to extend
operations within the currently permitted boundaries. In addition,
Capstone intends to immediately commission the necessary engineering
and economic studies to consider all remaining current mineral
resources in preparation for filing the permit applications.

Mineral Resource Estimate Methodology

The mineral resource estimate reported herein was prepared by Kirkham
Geosystems Ltd. of Burnaby, BC, Canada. The estimate was completed
using commercial mine planning software MineSight v7.50 using a three
dimensional block model (100 ft by 100 ft by 45 ft (vertical) block
size). The mineralization was interpreted into distinct domains,
modelled as wireframes and used as hard boundaries to constrain
estimation. Geostatistical analysis was completed on the 45 ft
composite assay data for each of the metals, and variograms were
defined for each domain of mineralization. The grades for copper and
molybdenum were interpolated into the block model using the ordinary
kriging method. Interpolated results are reported in measured,
indicated and inferred categories and are based on continuity of the
mineralization and sample density. The model was estimated in imperial
units and converted to metric units where appropriate for disclosure
purposes.

The mineral resources are confined within an optimized Lerchs-Grossman
(LG) pit shell to ensure reasonable prospects of economic extraction.
The pit shell was generated using a copper price of $3.30/lb, applied
to copper equivalent grade, with mining costs (ore and waste) of
$1.50/ton, processing costs of $5.00/ton and an overall pit slope of
45°. Copper equivalence (CuEq), used to constrain the pit, was
calculated using a ratio of Cu:Mo of 1:3.3, and recoveries of 88% and
50%, respectively. Mr. Kirkham is author of a Technical Report on the
Mineral Resource Estimate for the Pinto Valley resource estimate, to be
filed within 45 days of this news release. Mr. Kirkham is independent
of Capstone and is an “Independent Qualified Person” as defined by NI
43-101. Mr. Kirkham has reviewed and validated the resource information
contained in this release.

Advisors

Scotia Capital Inc. is acting as financial advisor to Capstone and its
Board of Directors. Capstone’s legal counsel is Blake, Cassels &
Graydon LLP and Davis, Graham & Stubbs LLP.

Pinto Valley Conference Call and Webcast

Capstone will hold a conference call and webcast on Monday April 29,
2013 at 11:00 am Eastern time (8:00 am Pacific time) for investors and
analysts, and at 1:00 pm Eastern time (10:00 am Pacific time) for
media.

Investors and Analysts

Date:	Monday, April 29, 2013
Time:	11:00 am Eastern Time — 8:00 am Pacific Time
Dial in:	North America: 1-888-390-0546, International: 1-416-764-8688
Slides:	http://capstonemining.com/s/Presentation.asp (the webcast includes the presentation slides)
Webcast:	http://event.on24.com/r.htm?e=615451&s=1&k=0CA36935ACBB5C42EFD7343A12A3A4B6
Replay:	North America: 1-888-390-0541, International: 1-416-764-8677
Replay Code:	500122

Media

Date:	Monday, April 29, 2013
Time:	1:00 pm Eastern Time — 10:00 am Pacific Time
Dial in:	North America: 1-888-390-0605, International: 1-416-764-8609
Slides:	http://capstonemining.com/s/Presentation.asp (the webcast includes the presentation slides)
Webcast:	http://event.on24.com/r.htm?e=615488&s=1&k=393BB64A7DEE379C2D11F3629A87D85E
Replay:	North America: 1-888-390-0541, International: 1-416-764-8677
Replay Code:	291320

The conference call replays will be available until May 13, 2013. The
investor conference call audio and transcript will be available on
Capstone’s website within approximately 24 hours of the call at http://capstonemining.com/s/Conference_Calls.asp.

Change to Capstone’s Q1 Financial Results Timing and Conference Call

Capstone will move the release of its first quarter financial results to
Tuesday, May 7, 2013 after market close, from May 8 as originally
scheduled. The conference call will also move by one day to Wednesday,
May 8. The Q1 conference call for investors and analysts will be held
at 11:30 am Eastern time (8:30 am Pacific time) on Wednesday, May 8,
2013. Please note the revised date below.

Date:	Wednesday, May 8, 2013
Time:	11:30 am Eastern Time — 8:30 am Pacific Time
Dial in:	North America: 1-888-390-0605, International: 1-416-764-8609
Webcast:	http://www.newswire.ca/en/webcast/detail/1134543/1237395
Replay:	North America: 1-888-390-0541, International: 1-416-764-8677
Replay Code:	378784

The conference call replay will be available until May 23, 2013. The
conference call audio and transcript will be available on Capstone’s
website within approximately 24 hours of the call at http://capstonemining.com/s/Conference_Calls.asp.

About Capstone Mining Corp.

Capstone Mining Corp. is a Canadian base metals mining company,
committed to the responsible development of our assets and the
environments in which we operate. We are preferentially focused on
copper, with two producing copper mines, the Cozamin
copper-silver-zinc-lead mine located in Zacatecas State, Mexico and the
Minto copper-gold-silver mine in Yukon, Canada. In addition, Capstone
has two development projects, the large scale 70% owned Santo Domingo
copper-iron-gold project in Chile in partnership with Korea Resources
Corporation and the 100% owned Kutcho copper-zinc-gold-silver project
in British Columbia, as well as exploration at properties in Canada,
Chile, Mexico and Australia. Using our cash flow and strong balance
sheet as a springboard, Capstone aims to grow with continued mineral
resource and reserve expansions, exploration, and through acquisitions
in politically stable, mining-friendly regions. Our headquarters are in
Vancouver, Canada and we are listed on the TSX. Further information is
available at www.capstonemining.com.

Cautionary Note Regarding Forward-Looking Information

This document may contain “forward-looking information” within the
meaning of Canadian securities legislation and “forward-looking
statements” within the meaning of the United States Private Securities
Litigation Reform Act of 1995 (collectively, “forward-looking
statements”). These forward-looking statements are made as of the date
of this document and Capstone Mining Corp. (the “Company”) does not
intend, and does not assume any obligation, to update these
forward-looking statements, except as required under applicable
securities legislation.

Forward-looking statements relate to future events or future performance
and reflect Company management’s expectations or beliefs regarding
future events and include, but are not limited to, statements with
respect to the estimation of mineral reserves and mineral resources,
the conversion of mineral resources to mineral reserves, the
anticipated date of closing of the acquisition of Pinto Valley and the
associated financing, the realization of mineral reserve estimates, the
timing and amount of estimated future production, costs of production,
capital expenditures, success of mining operations, environmental
risks, unanticipated reclamation expenses, title disputes or claims and
limitations on insurance coverage. In certain cases, forward-looking
statements can be identified by the use of words such as “plans”,
“expects” or “does not expect”, “is expected”, “outlook”, “budget”,
“scheduled”, “estimates”, “forecasts”, “intends”, “anticipates” or
“does not anticipate”, or “believes”, or variations of such words and
phrases or statements that certain actions, events or results “may”,
“could”, “would”, “might” or “will be taken”, “occur” or “be achieved”
or the negative of these terms or comparable terminology. In this
document certain forward-looking statements are identified by words
including “scheduled”, “guidance”, “plan”, “planned”, “estimated”,
“projections”, “projected” and “expected”. By their very nature
forward-looking statements involve known and unknown risks,
uncertainties and other factors which may cause the actual results,
performance or achievements of the Company to be materially different
from any future results, performance or achievements expressed or
implied by the forward-looking statements. Such factors include, among
others, risks related to actual results of current exploration
activities; changes in project parameters as plans continue to be
refined; future prices of mineral resources; possible variations in ore
reserves, grade or recovery rates; accidents; dependence on key
personnel; labour pool constraints; labour disputes; availability of
infrastructure required for the development of mining projects; delays
in obtaining governmental approvals or financing or in the completion
of development or construction activities; and other risks of the
mining industry as well as those factors detailed from time to time in
the Company’s interim and annual financial statements and management’s
discussion and analysis of those statements, all of which are filed and
available for review on SEDAR at www.sedar.com. Although the Company has attempted to identify important factors that
could cause actual actions, events or results to differ materially from
those described in forward-looking statements, there may be other
factors that cause actions, events or results not to be as anticipated,
estimated or intended. There can be no assurance that forward-looking
statements will prove to be accurate, as actual results and future
events could differ materially from those anticipated in such
statements. Accordingly, readers should not place undue reliance on
forward looking statements.

Quality Assurance and NI 43-101 Compliance

The technical information in this news release has been prepared in
accordance with Canadian regulatory requirements set out in National
Instrument 43-101 Standards of Disclosure for Mineral Projects of the
Canadian Securities Administrators (“NI 43-101”) and reviewed by John
Wright, P. Eng., Capstone’s Business Development Manager, a “Qualified
Person” under NI 43-101. The mineral resource estimate reported herein
for the Pinto Valley property was prepared by Garth Kirkham, P. Geo,
Kirkham Geosystems Ltd., an independent Qualified Person, from
information provided by BHP Billiton. BHP Billiton’s mineral reserve
estimate has been publicly reported in the BHP Billiton 2012 Annual
Report.

In addition, Gregg Bush, Senior Vice President and Chief Operating
Officer for Capstone Mining Corp. reviewed and approved this news
release.

Technical Report

A NI 43-101 compliant Technical Report related to the mineral resources
reported herein, will be filed under Capstone’s profile on SEDAR at www.sedar.com within 45 days.

Alternative Performance Measure

“Cash Cost per Pound of Copper” is an Alternative Performance Measure.
This performance measure is included because this statistic is a key
performance measure that management uses to monitor performance.
Management uses this statistic to assess how the Company is performing
to plan and to assess the overall effectiveness and efficiency of
mining operations. This performance measure does not have a meaning
within IFRS and, therefore, amounts presented may not be comparable to
similar data presented by other mining companies. This performance
measure should not be considered in isolation as a substitute for
measures of performance in accordance with IFRS.

Cautionary Note to United States Investors

This news release contains disclosure that has been prepared in
accordance with the requirements of Canadian securities laws, which
differ from the requirements of U.S. securities laws. Without limiting
the foregoing, this news release uses the terms “indicated” and
“inferred” resources. U.S. investors are cautioned that, while such
terms are recognized and required by Canadian securities laws, the SEC
does not recognize them. Under U.S. standards, mineralization may not
be classified as a “reserve” unless the determination has been made
that the mineralization could be economically and legally produced or
extracted at the time the reserve determination is made. U.S. investors
are cautioned not to assume that all or any part of indicated resources
will ever be converted into reserves. U.S. investors should also
understand that “inferred resources” have a great amount of uncertainty
as to their existence and as to whether they can be mined legally or
economically. It cannot be assumed that all or any part of “inferred
resources” will ever be upgraded to a higher category. Therefore, U.S.
investors are also cautioned not to assume that all or any part of
inferred resources exist, or that they can be mined legally or
economically. Accordingly, information concerning descriptions of
mineralization and resources contained in this news release may not be
comparable to information made public by U.S. companies subject to the
reporting and disclosure requirements of the SEC.

Note: All amounts in US$.

SOURCE Capstone Mining Corp.